Effect of carryover of clot activators on coagulation tests during phlebotomy.
Author(s): Fukugawa Y, Ohnishi H, Ishii T, Tanouchi A, Sano J, Miyawaki H, Kishino T, Ohtsuka K, Yoshino H, Watanabe T
Publication: Am J Clin Pathol, 2012, Vol. 137, Page 900-3
PubMed ID: 22586048 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of the addition of clot activator fluid to blood specimens in vitro on PT, aPTT, fibrinogen, D-dimer, and FMC measurements. Specimens were collected in sodium citrate Venoject II tubes, and clot activator fluid was added which had been prepared by adding saline to Venoject II tubes containing either thrombin and glass particles or only glass particles, or by adding saline to Vacutainer tubes containing silica particles. Coagulation testing was performed immediately after centrifugation.
Summary of Findings:
PT was significantly increased by the addition of any amount of clot activator fluid containing thrombin, glass particles, or silica particles, but all values were within 3% of the controls (saline added). aPTT was significantly decreased and FMC was significantly increased by the addition of thrombin clot activator fluid, and the changes were proportional to the amount of fluid added. The effects of glass and silica particle clot activator fluid on aPTT and FMC were minimal. Fibrinogen and D-dimer were generally not affected by the addition of any clot activator fluid, although some random significant changes were observed.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Glycoprotein Hematology/ auto analyzer Peptide Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Biospecimen components 2 uL clot activator fluid
5 uL clot activator fluid
10 uL clot activator fluid
2 uL saline
5 uL saline
10 uL saline
Thrombin and glass particles
Glass particles
Silica particles
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Study Purpose
The purpose of this study was to determine the effects of draw order when using a serum tube containing thrombin and glass particles and a coagulation tube containing sodium citrate on PT, aPTT, fibrinogen, D-dimer, and FMC measurements. Blood specimens were collected in the following order: plain tube with no additives, coagulation tube with sodium citrate, serum tube with thrombin and glass particles, and another coagulation tube. The butterfly needle inside the serum tube was purposefully soaked in the blood specimen during draw to maximize the possibility of clot activator contamination in the last coagulation tube.
Summary of Findings:
Among specimens from healthy volunteers and patients on warfarin, the average PT ratio and international normalized ration (INR) were lower in the coagulation tube drawn after the serum tube containing clot activator than in the coagulation tube drawn before the serum tube. For specimens from patients on warfarin, fibrinogen was significantly higher in the coagulation tube drawn after the serum tube compared to the one drawn before. No other differences in coagulation tests were noted between the two coagulation tubes for healthy volunteers or patients on warfarin.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
- Cardiovascular Disease
Platform:
Analyte Technology Platform Morphology Hematology/ auto analyzer Glycoprotein Hematology/ auto analyzer Peptide Hematology/ auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Preaquisition Other drugs Warfarin
None
Biospecimen Acquisition Type of collection container/solution Plain tube
Coagulation tube with sodium citrate
Serum tube with thrombin and glass particles
Biospecimen Aliquots and Components Aliquot sequential collection Plasma tube filled after plain tube
Plasma tube filled after serum tube containing clot activator